Radomes are highly electromagnetically transparent structures used for covering and protecting antennas. Antennas used in e.g. radar installations, wireless telecom infrastructure and radio telescopes often need a radome or a covering structure of some kind to protect them from weather, e.g. sunlight, wind and moisture. The presence of the radome is particularly mandatory for antennas placed in regions where high winds or storms often occur, in order to protect the antennas from hale and impacts from projectiles such as debris carried by the wind.
A special kind of radomes is an inflatable radome, which is particularly used to protect portable antennas. An inflatable radome most often can be easily packed, shipped and quickly deployed and is typically manufactured from a flexible membrane. It is preferred that the flexible membrane is designed to resist times and again to stresses induced by repetitive inflation-deflation cycles, and to have a good tearing and/or abrasion resistance. At the same time said membrane needs to have good electromagnetic properties in order to least interfere with passing electromagnetic waves.
An inflatable radome is known for example from US 2004/0222938, said radome being used to protect and stabilize the orientation of an inflatable antenna. Further disclosures of inflatable radomes are given in U.S. Pat. No. 3,005,987 and U.S. Pat. No. 3,075,191. It was however observed that the known radomes when inflated may have difficulties in preserving their shape during utilization and in particular during long-term utilization. Exposure to sunlight, temperature variations, humidity, wind and other environmental factors acting on inflatable radomes may lead to alterations of the originally intended radome's shape. It was also observed that when the shape of the radome is altered during use, the efficiency of the antenna/radome system may decrease.
Therefore an aim of the present invention may be to provide an inflatable radome which preserves its shape during use and in particular during long-term use. A further aim of the invention may be to provide an inflatable radome which resists to alterations of its shape while at the same time is lightweight, strong and has good electromagnetic properties. Another aim of the invention may be to provide an inflatable radome that is less prone to being damaged and therefore to deflate and/or collapse. Yet another aim of the invention is to provide an inflatable radome having a reduced loss over wide frequency bandwidths, e.g. from 1 GHz to at least 100 GHz.